SS tumbling affecting neck tension?

[thisguy65]

My question pertains to the cases hitting one another and causing the necks to become oblong or change dimension that were set by the sizing die. I do not turn necks. I'm just curious if anyone has had this problem. It's a concern of mine ever since I got a bigger tumbler that tumbles brass alot faster than my old setup.

 

[Lee Martin]

Have you quantified this? Meaning, isolate a case after sizing (maybe by seating a spent primer in just that shell) and tumble. Measure the neck before and after. That should answer your question. I doubt they change much. And if they do, it'll be hard to prove that it's the tumbling vs. slight spring back.

-Lee
www.singleactions.com

 

[CMaier]

stuff moves way too slow, pins are very light.
pins support the case from banging into each other.
they may touch but no velocity.

 

[Mozella]

..... snip..... It's a concern of mine ...... snip.

I run a neck turning mandrel down the neck after sizing, cleaning, and annealing; i.e. during the priming process. That helps insure a round and uniform neck. Of course it requires a mandrel of the correct diameter in order to produce the neck tension you're looking for. You could give that a try even if you don't turn necks.

 

[thisguy65]

Have you quantified this? Meaning, isolate a case after sizing (maybe by seating a spent primer in just that shell) and tumble. Measure the neck before and after. That should answer your question. I doubt they change much. And if they do, it'll be hard to prove that it's the tumbling vs. slight spring back.

-Lee
www.singleactions.com

I haven't done as much testing as I would like. I was more or less fishing to see if anyone has experience this. The brass I processed last night is virgin that I just neck size using a FL/Bushing die. However 2 weeks ago when I got the tumbler (added the 5 lbs of pins) is when this started on brass that was 3X fired, annealed and trimmed to length after every firing. When I notice the change. My old tumbler moves a lot slower (RPM) compare to the frankford. It just hauls ass..lol

stuff moves way too slow, pins are very light.
pins support the case from banging into each other.
they may touch but no velocity.

I run a neck turning mandrel down the neck after sizing, cleaning, and annealing; i.e. during the priming process. That helps insure a round and uniform neck. Of course it requires a mandrel of the correct diameter in order to produce the neck tension you're looking for. You could give that a try even if you don't turn necks.

I have a .002 undersized mandrel for .308, .223, 6.5 creedmoor now that I use to get the necks round before putting them in the FL/Bushing die. I may be trying to split hairs..the SD is around 5-6 and ES of 18 when I last testing the load (lot powder change). With the older powder I was getting lower number. Went down .2 grains and still got the same SD/ES with the new lot of powder, so I know I was still in the node. Was 10fps faster too.

 

[BenPerfected]

My question pertains to the cases hitting one another and causing the necks to become oblong or change dimension that were set by the sizing die. I do not turn necks. I'm just curious if anyone has had this problem. It's a concern of mine ever since I got a bigger tumbler that tumbles brass alot faster than my old setup.[/QUOTE

After SS tumbling I lightly touch up the chamfer in/out. No proof it improves accuracy but it makes for a more consistent feel when seating the bullets.
Ben

 

[Dusty Stevens]

+1. Gotta re do the de bur and fl size after tumbling and deburring

 

[Nor Cal Mikie]

The SS pins WILL wear brass. I've seen "gold dust" on the edges of the tumbler drum. Best to NOT use the SS treatment all the time. Maybe every third or fourth cleaning or even less.
Once you get the inside of the case clean, you might just wipe the outside clean.

 

[Mozella]

The SS pins WILL wear brass. I've seen "gold dust" on the edges of the tumbler drum. Best to NOT use the SS treatment all the time. Maybe every third or fourth cleaning or even less.
Once you get the inside of the case clean, you might just wipe the outside clean.

This advice makes no sense to me. The whole idea of wet SS tumbling is to clean brass IN A BATCH. The most tedious parts of hand loading nearly always handling brass one case at a time. That's why I do NOT clean each case individually, even with a casual wipe down.

Of course, I individually charge each case with a carefully weighed charge of powder; that's unavoidable. But I'm always looking for methods to reduce individual case handling, not increase it.

I'm not saying wet SS doesn't wear brass. It's bound to, at least so some tiny degree. But I know that it doesn't wear the cases out.

I anneal every time and I enjoy such long brass life that I don't count how many times each case is reloaded. But I do know that the answer is "many many" times. I wet SS tumble each time too and I've never worn a hole in a case.

I too see "gold dust" when I clean brass, but I'm quite sure it's the result of neck trimming, chamfering, and the small shavings occasionally associated with primer seating. Any wear caused by the SS pins is certainly tiny by comparison and not of any concern, at least not to me.

 

[CMaier]

There are pins and there are pins.
Some cheap pins are simply sheared wire with sharp edges.
Some are smooth ends.
I think cheap sharp edged pins might cause some brass dust.
I have not seen it in my batches

 

[Edward Horton]

Below are new unfired cases that have not been sized or trimmed to length, just as they came from the factory.

Below are once fired cases after being wet tumbled with stainless steel media. You can see the dings in the case mouth from the cases hitting each other.

Below is what happens when you fall asleep and let the cases wet tumble for seven hours.

So wet tumble, trim, chamfer, resize and pre-tumble new pins overnight to wear down the sharp ends and don't fall asleep when tumbling.

 

[Edward Horton]

Great pictures, Mr. Horton.
What size tumbling media and what sort of tumbler do you use? Ours is a rather large drum that tumbles slowly. Ours is more like a concrete mixer without the interior paddles. I need to learn to take and post pictures.
And welcome to the forum.

FBecigneul

I'm 65 with chronologically gifted eyesight and didn't know the case mouths looked that bad until I took a closeup macro photo. I have the STM Thumler's Tumbler Model B High Speed and the media size is .047x.255. And it is very important to pre-tumble the pins to wear down the sharp ends. The pins are so sharp when you pre-tumble without any brass the water turns black from abrading the black rubber liner.

I sent a new rubber liner to a friend in Canada who tumbled so much he wore a hole in the rubber liner. So what the tumblers are lined with is something to think about when selecting a tumbler for constant use.

Many shooters say they do not like removing the carbon from the insides of the case necks as it effects bullet release. This is easy to fix by dipping the case necks in powdered graphite which is nothing more than a crystalline form of carbon when sizing.